Improved Silverlight Migration Edition: keyboard and mouse events now have same name and signature as in SL ("MouseLeftButtonDown" instead of "PointerPressed", etc.), IValueConverter has same signature as in SL, GetPosition works like in SL, the visual states are more similar to SL, and many more compatibility improvements with Silverlight.

MatrixTransform

Keyboard.Modifiers and ability to get the key modifiers (such as ctrl, shift) in the key and mouse event handlers

Support for Byte Array serialization and deserialization, and ability to pass byte arrays in WPF SOAP web service calls

Ability to load an image from a byte array, where the byte array contains the bytes of a JPG or PNG file.Note: in case of large images, it is still recommended to load the image from a URL instead of a byte array/stream, to ensure the best memory consumption and performance.

New "HtmlPresenter.DomElement" property to get a reference to the instantiated DIV to pass to the ExecuteJavaScript method.

Support for Decoder.GetChars(), Decoder.GetCharCount(), and Encoding.GetDecorder(), as documented here

DataGridColumn.Visibility (Ability to show/hide individual columns in the DataGrid)